This trial is designed to evaluate the immunomodulatory, toxic and antitumor effects of the combination of flavone-8 acetic acid (FAA) and interleukin-2 (IL-2). FAA as a single agent is curative for early and advanced murine colon 38 and has activity in several other murine solid tumor models. Interestingly, FAA has only modest direct cytotoxicity. In a murine renal cell carcinoma model, the combination of FAA + IL-2 is curative when neither FAA nor IL-2 alone at the same doses are active. Immunologic studies in mice and humans have shown that FAA boosts natural killer cell activity and increases serum interferon levels. FAA has been studied as a single agent in phase I clinical trials, without evidence of clinical activity. Twenty-two patients have completed the trial. No consistent immunomodulatory or antitumor effects have been observed. FAA is a weak acid and, to avoid drug precipitation in renal tubules, was given after urinary alkalinization, a maneuver that was not employed in the animal studies. Subsequent animal studies showed ablation of the immunomodulatory and antitumor effects of FAA plus IL-2 when the animal's urine was alkalinized. The protocol was modified to infuse the FAA over shorter periods of time (1 and 3 hour intervals) and to delete urinary alkalization. In this modification, 12 patients were entered on trial (4 colon, 2 melanoma, 1 rectal, and 5 renal cell cancer). Of these, 2 still remain on treatment. The trial continues to define an MTD of FAA by 1-hour infusion once weekly, in combination with IL-2 at a fixed dose of 3x106 u/m2 twice weekly, in this regimen. No antitumor responses have been seen. In the patients treated with 3-hour FAA infusion, some enhancement of NK and LAK activity was seen during the period of combined FAA and IL-2 therapy, but not during the initial 3-week period during which they were treated with FAA alone. More detailed analysis of immune modulatory data is continuing, as patients are accrued to other FAA dosage levels.